首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   327659篇
  免费   63163篇
  国内免费   18233篇
耳鼻咽喉   3747篇
儿科学   6680篇
妇产科学   3851篇
基础医学   44397篇
口腔科学   9256篇
临床医学   46869篇
内科学   59213篇
皮肤病学   9777篇
神经病学   26218篇
特种医学   11465篇
外国民族医学   147篇
外科学   37681篇
综合类   44165篇
现状与发展   61篇
一般理论   44篇
预防医学   20530篇
眼科学   8466篇
药学   31850篇
  233篇
中国医学   16172篇
肿瘤学   28233篇
  2024年   864篇
  2023年   4065篇
  2022年   10399篇
  2021年   14340篇
  2020年   14561篇
  2019年   18764篇
  2018年   18636篇
  2017年   19085篇
  2016年   19063篇
  2015年   23009篇
  2014年   25626篇
  2013年   24339篇
  2012年   22459篇
  2011年   24515篇
  2010年   21180篇
  2009年   14950篇
  2008年   14987篇
  2007年   14035篇
  2006年   13982篇
  2005年   13686篇
  2004年   9304篇
  2003年   9186篇
  2002年   8056篇
  2001年   7178篇
  2000年   6940篇
  1999年   6637篇
  1998年   3903篇
  1997年   3901篇
  1996年   3113篇
  1995年   2864篇
  1994年   2352篇
  1993年   1498篇
  1992年   2026篇
  1991年   1719篇
  1990年   1385篇
  1989年   1164篇
  1988年   1092篇
  1987年   953篇
  1986年   789篇
  1985年   570篇
  1984年   355篇
  1983年   261篇
  1982年   161篇
  1981年   157篇
  1980年   121篇
  1979年   157篇
  1978年   54篇
  1977年   59篇
  1975年   59篇
  1974年   62篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
Abstract: We have designed and synthesized a new series of azapeptides which act as potential inhibitors of cathepsin B and/or cathepsin K. Their structures are based upon the inhibitory sites of natural cysteine protease inhibitors, cystatins. For the synthesized azapeptides, the equilibrium constants for dissociation of inhibitor–enzyme complex, Ki, were determined. Comparison of these values indicated that all of the azainhibitors act much stronger toward cathepsin B. Z‐Arg‐Leu‐His‐Agly‐Ile‐Val‐OMe ( 7 ) proved to be approximately 500 times more potent for cathepsin B than for cathepsin K. To be able to explain the obtained experimental values we used the molecular dynamics procedures to analyze the interactions between cathepsin B and compound 7 . We also determined the structure of the most potent and selective cathepsin B azainhibitor by means of NMR studies and theoretical calculations. In this report, we describe SAR studies of azapeptide inhibitors indicating the influence of the conformational flexibility of the examined compounds on inhibition of cathepsins B and K.  相似文献   
53.
54.
Erratum     
  相似文献   
55.
The authors reviewed the radiographic manifestations of 17 cases of parosteal osteosarcoma, with pathologic correlation in 15. There were two types of parosteal osteosarcoma radiologically. The majority of cases were type I with uniformly dense masses which had regular borders. They often adhered to the cortex and showed no evidence of soft-tissue invasion which correlated with low-grade pathologic malignancy and a relatively benign clinical course. Type II involved the bone, soft-tissue and the medullary cavity. These lesions were poorly differentiated and frequently accompanied by metastatic lesions.
  相似文献   
56.
1 The internal anal sphincter (IAS) has a spontaneous tone and is the main contributor to the maintenance of faecal continence. The spontaneous resting tone exhibited by the sphincter can be modified by neurotransmitters from the autonomic and enteric nervous systems. 2 In this review, the influence of the sympathetic and parasympathetic nervous systems on IAS tone are discussed and the putative roles of nitric oxide, carbon monoxide, vasoactive intestinal peptide and adenosine triphosphate in non‐adrenergic non‐cholinergic transmission are considered. 3 Faecal incontinence is a common condition that places a heavy financial burden on the health service and severely affects patients’ quality of life. Resting anal pressure is reduced in patients with faecal incontinence and agents that increase sphincter tone tend to relieve symptoms. The results of clinical studies of the use of phenylephrine to treat faecal incontinence are reviewed. 4 It is concluded that the IAS is a potential target for drug development for the treatment of faecal incontinence.  相似文献   
57.
58.
59.
This study evaluated the safety and efficacy of batroxobin in treating hyperfibrinogenemia for secondary stroke prevention. Patients with ischemic stroke or transient ischemic attack (TIA) were measured for plasma fibrinogen levels. Selected participants had concomitant hyperfibrinogenemia (plasma fibrinogen > or = 3.0 g/l). Patients enrolled between 1 July 2003 and 31 December 2004 were treated with batroxobin; patients enrolled between 1 January 2002 and 30 June 2003 were treated without batroxobin. Batroxobin was administered intermittently via intravenous injection at 3-monthly intervals. Patients in both groups were followed for 1 year. Any cerebrovascular events and suspected adverse events were recorded. In total, 112 ischemic stroke/TIA patients with concomitant hyperfibrinogenemia were enrolled, 52 being treated with batroxobin and 60 without batroxobin. Six patients (11.5%) with batroxobin and 16 patients (26.7%) without batroxobin had recurrent cerebral ischemic events during follow-up. Stroke/TIA recurrence in patients without batroxobin was higher than that in patients with batroxobin (P < 0.05). Two patients with batroxobin and two patients without batroxobin developed hemorrhagic stroke during follow-up. There were five deaths (9.6%) in the batroxobin group, and seven deaths (11.7%) in the nonbatroxobin group during follow-up (P > 0.05). Intermittent intravenous injection of batroxobin can efficiently reduce the risk for stroke/TIA recurrence in patients with concomitant hyperfibrinogenemia.  相似文献   
60.
刘振举 《护理研究》2007,21(12):1108-1109
一般护理记录单是住院病历的一部分,根据卫生部、中医药管理局公布的《病历书写基本规范》(试行)的规定,一般护理记录的定义是:护士根据医嘱和病情对一般病人住院期间护理过程的客观记录,内容包括病人姓名、记录日期和时间、病情观察、护理措施和效果、护士签名。现将护士在一般护理书写中存在认识上的理解偏差分析如下。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号